The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 02, 1977
Filed:
Mar. 22, 1976
Robert A Couturier, Stamford, CT (US);
Steven J Davis, Ridgefield, CT (US);
G Howard Robbins, New Canaan, CT (US);
General Datacomm Industries, Inc., Wilton, CT (US);
Abstract
A method and apparatus are disclosed for closed loop testing of first and second modulators and demodulators from the modulated signal side of the first modulator and first demodulator. During ordinary communication, the first modulator and second demodulator are connected in series and the first demodulator and the second modulator are connected in series. In response to each test initiate signal, a loop is established between the second modulator and the second demodulator on their modulated signal side. Upon reception of some test initiate signals, a loop is established between the first modulator and first demodulator on their demodulated side and they are disconnected from the second demodulator and second modulator. Thus, the first modulator and demodulator can be tested from their modulated signal side when a loop is established between them; and the first and second modulators and demodulators can be tested when a loop is established between the second modulator and demodulator but not between the first modulator and demodulator.